Blend half of the mango into a purée. Mix the rolled oats (or chia seeds, if you prefer), milk (yoghurt, kefir or plant-based milk), mango purée, sugar, salt and spices in a bowl, cover with cling film and leave in the fridge overnight. In the morning, stir and add a little more sugar if it is not sweet enough, or more milk if it is too thick. Transfer to a serving glass, top with the remaining half of the mango cut into cubes and drizzle with date syrup. You can also dust it with a little icing sugar, but only a little.